#===============================================================================
# This file is part of the "Parallel Location and Exchange" library,
# intended to provide mesh or particle-based code coupling services.
#
# Copyright (C) 2005-2024  EDF S.A.
#
# This library is free software; you can redistribute it and/or
# modify it under the terms of the GNU Lesser General Public
# License as published by the Free Software Foundation; either
# version 2.1 of the License, or (at your option) any later version.
#
# This library is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
# Lesser General Public License for more details.
#
# You should have received a copy of the GNU Lesser General Public
# License along with this library; if not, write to the Free Software
# Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
#===============================================================================

#===============================================================================
# MPI utilities for easier use by external codes.
#===============================================================================

def mpi_initialized():
    """
    This function checks if the python script was launched with MPI.
    """

    try:
        import mpi4py
    except ImportError:
        return False

    try:
        import mpi4py.MPI
    except ImportError:
        return False

    if mpi4py.MPI.COMM_WORLD.size == 1 and mpi4py.MPI.COMM_WORLD.rank == 0:
        return False

    return True

#-------------------------------------------------------------------------------

def get_comm_world():
    """
    This function returns the MPI_COMM_WORLD communicator which can then
    be used in Python for the different MPI operations.
    """

    from mpi4py import MPI

    base_comm = MPI.COMM_WORLD

    return base_comm

#-------------------------------------------------------------------------------
